add oversampler

oversampling/WDL/bitfield.h

@@ -0,0 +1,34 @@
+#ifndef _WDL_BITFIELD_H_
+#define _WDL_BITFIELD_H_
+
+#include "heapbuf.h"
+
+class WDL_BitField  // ultra simple bit field
+{
+public:
+  bool SetSize(int sz) // clears state
+  {
+    void *b=m_hb.ResizeOK((sz+7)/8);
+    if (b) memset(b,0,m_hb.GetSize());
+    return !!b;
+  }
+  int GetApproxSize() const { return m_hb.GetSize()*8; } // may return slightly greater than the size set
+
+  bool IsSet(unsigned int idx) const 
+  { 
+    const unsigned char mask = 1<<(idx&7);
+    idx>>=3;
+    return idx < (unsigned int)m_hb.GetSize() && (((unsigned char *)m_hb.Get())[idx]&mask);
+  }
+  void Set(unsigned int idx)
+  {
+    const unsigned char mask = 1<<(idx&7);
+    idx>>=3;
+    if (idx < (unsigned int)m_hb.GetSize()) ((unsigned char *)m_hb.Get())[idx] |= mask;
+  }
+
+private:
+  WDL_HeapBuf m_hb;
+};
+
+#endif //_WDL_BITFIELD_H_